World Timezones

IRST to GMT Converter

Compare GMT to IRST instead
Iran Standard Time8:06 amFri, Jun 5
Iran Standard TimeIRST
Middle East · UTC+3:30
8:06 amFri, Jun 5
12a
1a
2a
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4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
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6p
7p
8p
9p
10p
11p
Greenwich Mean TimeBST
Europe · UTC+1
5:36 amFri, Jun 5
9p
10p
11p
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
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5p
6p
7p
8p

Offset

The time difference between Iran Standard Time and Greenwich Mean Time is 2.5 hours.

2.5 hours

Iran Standard Time (IRST) is ahead of Greenwich Mean Time (BST).

IRST: UTC+3:30

BST: UTC+1

Greenwich Mean Time is currently observing daylight saving time; Iran Standard Time is not.

When to schedule

Business-hours overlap: 12 PM–5 PM in Iran Standard Time (9 AM–2 PM in Greenwich Mean Time).

Both teams are in working hours during this window on weekdays.

Suggested time: 2:00 PM Iran Standard Time (11:30 AM Greenwich Mean Time).

This window may shift by an hour during daylight saving time.

Public holidays in 2026

National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.

United Kingdom

  • Good FridayFri, Apr 3
  • Early May Bank HolidayMon, May 4
  • Spring Bank HolidayMon, May 25
  • Christmas DayFri, Dec 25
  • St. Stephen's DayMon, Dec 28

About these zones

Iran Standard Time is also known as IRST. To call Iran, dial +98.

Greenwich Mean Time is also known as GMT, or BST. To call United Kingdom, dial +44.

Greenwich Mean Time is approximately 2,750 miles northwest of Iran Standard Time.

Quick reference

Full 24-hour conversion table — tap any time to open it in the converter.

IRSTGMTDay
12:00 am9:30 pm-1 day
1:00 am10:30 pm-1 day
2:00 am11:30 pm-1 day
3:00 am12:30 amSame day
4:00 am1:30 amSame day
5:00 am2:30 amSame day
6:00 am3:30 amSame day
7:00 am4:30 amSame day
8:00 am5:30 amSame day
9:00 am6:30 amSame day
10:00 am7:30 amSame day
11:00 am8:30 amSame day
12:00 pm9:30 amSame day
1:00 pm10:30 amSame day
2:00 pm11:30 amSame day
3:00 pm12:30 pmSame day
4:00 pm1:30 pmSame day
5:00 pm2:30 pmSame day
6:00 pm3:30 pmSame day
7:00 pm4:30 pmSame day
8:00 pm5:30 pmSame day
9:00 pm6:30 pmSame day
10:00 pm7:30 pmSame day
11:00 pm8:30 pmSame day

Daylight saving time

Greenwich Mean Time observes daylight saving time; Iran Standard Time does not. The offset between the two zones changes when Greenwich Mean Time transitions: on Sunday, October 25, 2026, clocks fall back from BST to GMT.

See the daylight saving time page for transition dates across every time zone.

Daylight today

Iran Standard Time
Sunrise
4:50 AM
Sunset
7:18 PM
Day length
14h 28m
Greenwich Mean Time
Sunrise
4:47 AM
Sunset
9:13 PM
Day length
16h 25m

Daylight overlap: 12h — 7:17 AM–7:18 PM in Iran Standard Time (4:47 AM–4:48 PM in Greenwich Mean Time). Both locations are in daylight during this window.

Cities in these zones

Cities in Iran Standard Time

Browse all cities to see the current local time anywhere.

Airports in these zones

Airports in Iran Standard Time

  • IKA
  • THR
  • MHD
  • IFN
  • PYK
  • TBZ

Airports in Greenwich Mean Time

  • LCY
  • LGW
  • LHR
  • LTN
  • STN
  • BHX
  • EMA
  • GLA
  • PIK
  • LBA

Related conversions

Common conversions

What is 9:00 am IRST in GMT?
9:00 am IRST is 6:30 am GMT.
What is 12:00 pm IRST in GMT?
12:00 pm IRST is 9:30 am GMT.
What is 12:30 pm IRST in GMT?
12:30 pm IRST is 10:00 am GMT.
What is 2:00 pm IRST in GMT?
2:00 pm IRST is 11:30 am GMT.
What is 5:00 pm IRST in GMT?
5:00 pm IRST is 2:30 pm GMT.
What is 11:30 pm IRST in GMT?
11:30 pm IRST is 9:00 pm GMT.